Any Home. Any Season. One System.
Upgrade to a high-efficiency heat pump to heat and cool with one system, reduce energy costs, and get up to $7,500 in rebates.
Hot Water
Without the Wait
Upgrade to a high-efficiency tankless for just $39.96/month or $3,596 outright and enjoy unlimited hot water, lower bills, and more space.
Rinnai Tankless
Rinnai tankless water heaters, known as the best quality tankless system and a best seller in North America, last twice as long as tanks and have double the warranty length.
3-Month No Payment No Interest
worry-free 10-year warranty.
Rinnai Tankless Water Heater
Rinnai RXP160IN Tankless SENSEI® Recirculation Built-In
The Rinnai RXP160iN is a 160,000 BTU super high-efficiency tankless water heater with a built-in recirculation pump for faster hot water. Delivering up to 9.0 GPM, it’s ideal for medium homes with up to two bathrooms. Professionally installed by 4Most Energy in the Greater Toronto Area and Southern Ontario.
Rinnai RXP199IN Tankless SENSEI® Recirculation Built-In
The Rinnai RXP199iN is a 199,000 BTU super high-efficiency tankless water heater with a built-in recirculation pump for faster hot water. Delivering up to 11.1 GPM, it’s ideal for larger homes with multiple bathrooms. Professionally installed by 4Most Energy in the Greater Toronto Area and Southern Ontario.
Navien Tankless
The Navien tankless water heater utilizes state-of-the-art technology to deliver a dependable, efficient hot water solution. It is an ideal option for homeowners prioritizing modern, efficient, and environmentally friendly water heating.
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3-Month No Payment No Interest
worry-free 10-year warranty.
Navien Tankless Water Heater
Tankless Water Heater
Endless Hot Water. Real Savings. 4Most Energy Delivers It All.
Upgrading to a tankless water heater isn’t just about comfort—it’s about choosing a smarter, more reliable system installed by Ontario pros. At 4Most Energy, we don’t just sell equipment. We size your home correctly, handle permits and professional installation, and stand behind our work with clear pricing and no hidden fees. Get on-demand hot water, lower bills, and more space—plus support you can count on across the GTA.
Why Ontario Homeowners Choose Go Lime For Their Tankless Water Heater
✔ Expert Sizing & Real Solutions — Not Guesswork
We calculate your exact GPM demand, winter inlet temperature, and gas sizing to ensure the perfect system for your home. No upselling. No unnecessary add-ons.
✔ Fast, Professional Installation
Licensed Ontario technicians handle gas line upgrades, venting, condensate, and full safety testing. Done once, done right.
✔ Transparent Pricing With No Hidden Fees
You get clear, all-inclusive quotes covering everything needed for a proper tankless installation. No surprise charges, ever.
✔ Industry-Leading Warranty Protection
Every installation includes: 1-year labor warranty (extendable to 10 years) Up to 10-year manufacturer parts warranty. Full support, maintenance reminders, and priority service through 4Most Energy
✔ Same-Day Official Estimate
Submit your project details and receive a professional quote within 20 minutes, including equipment options, pros/cons, and total installation pricing.
✔ Top-Rated Customer Service in the GTA
Our customers consistently highlight our fast communication, clean installations, honest recommendations, and friendly team.
About Rinnai & Navien Tankless Systems
4Most Energy Tankless FAQs
Why is 4Most Energy the best Navien and Rinnai installer in Ontario?
4Most Energy is a top choice for Navien and Rinnai installations because:
10+ years of boiler & tankless experience
Fully manufacturer-trained and certified installers
Authorized to claim Navien & Rinnai warranty
Experts at fixing installation errors from other companies
Same-day emergency support across the GTA
Honest, brand-neutral recommendations based on your home
Proper solutions for any water-heating system, regardless of brand availability
Professional installation, fast service, and full warranty protection make 4Most Energy one of Ontario’s most trusted tankless specialists.
How can I get the best price on a Rinnai or Navien tankless system?
4Most Energy checks current factory promotions, supplier discounts, and in-stock models before giving you a quote. We always recommend the option with the best performance at the lowest cost at that moment.
What’s included in a 4Most Energy tankless installation?
Gas line upgrade (if needed)
Venting system
Condensate pump/drain
Isolation valves
Stainless steel flex lines
Commissioning & system testing
Warranty registration
1-year labour coverage
No hidden add-ons.
How long have you been in business?
4Most Energy’s licensed technicians have 15+ years of combined experience installing boilers, tankless water heaters, and heat pumps across Ontario. Our service is backed by hundreds of 5-star Google Reviews.
Rinnai vs Navien: Which brand is better for my home?
Both Rinnai and Navien are top-performing tankless brands, but each has unique advantages:
Rinnai (Premium Reliability)
Industry-leading Japanese engineering
Longest lifespan in the market
Extremely low failure rate
Quieter operation
Best choice if long-term durability is your priority
Navien (Best Features & Value)
Built-in recirculation on many models (faster hot water)
Stainless steel heat exchanger
Strong performance for multi-bathroom homes
Often more cost-effective
4Most Energy installs both brands based on the size of your home, hot-water demand, and venting/gas requirements—not upselling.
What tankless size do I need for my home?
Tankless sizing depends on:
Number of bathrooms
Shower flow rates
Peak hot-water usage (GPM)
Winter inlet temperature in Ontario
Home layout
General guideline for Ontario homes:
1 bathroom / condo → 120,000–150,000 BTU
2 bathrooms / townhome → 150,000–180,000 BTU
3+ bathrooms / detached home → 180,000–199,000 BTU
Large homes / multi-showers → 199,000 BTU or dual tankless in parallel
4Most Energy provides the correct GPM calculation and recommends the ideal Navien or Rinnai model for your home.
What warranty do I get with a tankless water heater?
All 4Most Energy installations include:
1-year labour warranty (extendable to 10 years)
Up to 10-year manufacturer parts warranty
Heat exchanger warranty:
Rinnai → up to 15 years
Navien → up to 15 years
Full warranty registration by our team
Priority support & service across the GTA
Your system is fully protected long-term.
Which tankless water heater works best with air handlers?
Rinnai performs best with air handlers and hydronic coils.
It provides:
Stable hot-water supply
Consistent flow
High reliability for heating systems
If your home uses an air handler for heating, Rinnai is usually the better choice.
Which tankless is better for recirculation and reducing hot-water delay?
Navien is the best option for homes with:
Long plumbing runs
Slow hot-water delivery
Multiple bathrooms
Need for faster recirculation
Many Navien units include a built-in recirculation pump, giving quicker hot water at remote taps.
How often do Navien and Rinnai tankless systems need maintenance?
Maintenance needs depend on Ontario water quality and usage.
Recommended Schedule:
Descaling every 3–5 years (hard water = every 3 years)
Annual system check including:
Vent inspection
Air intake filter cleaning
Cold-water inlet filter cleaning
Gas pressure testing
Condensate drain inspection
Ignition system cleanup
Checking for restrictions or leaks
This ensures maximum performance and extends lifespan.
Why 4Most Energy Is Ontario’s Trusted Choice for Home Comfort
Local & Reliable
Proudly serving GTA homeowners with trusted service, extended maintenance, and real local support.
Clear, Upfront Pricing
Know your total cost before installation. No hidden fees just honest, transparent quotes.
Expert Advice, Not Sales Talk
You’ll always speak directly with a licensed HVAC expert never a call center or salesperson.
Fast, Professional Installation
Same-day or next-day installs by certified technicians, done right the first time.
Flexible Financing Options
Upgrade your system with affordable monthly plans — no large upfront payment required.
Service calls starting at $89.00
Repair & Service Call
Fast, Honest Repairs You Can Trust.
When your system needs attention, 4Most Energy is just a call away.
Our licensed technicians diagnose the issue, explain it clearly, and give you a transparent cost before any work begins
No hidden fees or upselling
We repair, not replace unless necessary
Servicing water heaters, tankless units, and boilers
Extended Labour Warranty
Extend Your Protection. Enjoy Peace of Mind.
Add extra coverage beyond your standard installation warranty.
With our Extended Labour Warranty, all service and labour costs are covered — so you stay protected from unexpected expenses for years to come.
Coverage for installation and labour
Zero repair costs during warranty period
Optional multi-year protection plans available
Backed by certified 4Most Energy technicians
Get Your Tankless Quote Quickly & Confidently
We understand that requesting a quote is the first crucial step toward a comfortable home.
Fast Response: Our dedicated team prioritizes quote requests. Expect a call or email within one business day to confirm your details.
Expert Guidance: We handle everything from high-efficiency replacements to new installations. We'll ensure the boiler we recommend is perfectly sized and meets all Ontario safety standards.
No Obligation: Submitting this form is free. We provide transparent pricing and expert advice so you can make an informed decision.
Request Your 20-Minute Estimate
Our boiler expert will review your info, prepare an official estimate, and contact you within 20 minutes
Check Your Home’s Compatibility & Installation Price
No hidden fees. Just accurate math based on your home’s specs.
Talk to a Real Technician
kip the call centers connect directly with a certified HVAC pro for honest answers.
Local Service You Can Count On
We’re proudly serving homes across the GTA fast response, trusted results.
Smarter Payment Options
Spread your cost with flexible monthly plans no surprises, just simple comfort.
Share Comfort, Get Rewarded
Invite friends or family when they book with us, you’ll both benefit.
